summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/glue.c
blob: 1564e0927c21de130cd134be6371161298709b5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/*
 * Link physical devices with ACPI devices support
 *
 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (c) 2005 Intel Corp.
 *
 * This file is released under the GPLv2.
 */
#include <linux/export.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>

#include "internal.h"

#define ACPI_GLUE_DEBUG	0
#if ACPI_GLUE_DEBUG
#define DBG(x...) printk(PREFIX x)
#else
#define DBG(x...) do { } while(0)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);

int register_acpi_bus_type(struct acpi_bus_type *type)
{
	if (acpi_disabled)
		return -ENODEV;
	if (type && type->bus && type->find_device) {
		down_write(&bus_type_sem);
		list_add_tail(&type->list, &bus_type_list);
		up_write(&bus_type_sem);
		printk(KERN_INFO PREFIX "bus type %s registered\n",
		       type->bus->name);
		return 0;
	}
	return -ENODEV;
}

int unregister_acpi_bus_type(struct acpi_bus_type *type)
{
	if (acpi_disabled)
		return 0;
	if (type) {
		down_write(&bus_type_sem);
		list_del_init(&type->list);
		up_write(&bus_type_sem);
		printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
		       type->bus->name);
		return 0;
	}
	return -ENODEV;
}

static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
{
	struct acpi_bus_type *tmp, *ret = NULL;

	down_read(&bus_type_sem);
	list_for_each_entry(tmp, &bus_type_list, list) {
		if (tmp->bus == type) {
			ret = tmp;
			break;
		}
	}
	up_read(&bus_type_sem);
	return ret;
}
EXPORT_SYMBOL_GPL(register_acpi_bus_type);

static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
{
	struct acpi_bus_type *tmp;
	int ret = -ENODEV;

	down_read(&bus_type_sem);
	list_for_each_entry(tmp, &bus_type_list, list) {
		if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
			ret = 0;
			break;
		}
	}
	up_read(&bus_type_sem);
	return ret;
}
EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);

/* Get device's handler per its address under its parent */
struct acpi_find_child {
	acpi_handle handle;
	u64 address;
};

static acpi_status
do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	acpi_status status;
	struct acpi_device_info *info;
	struct acpi_find_child *find = context;

	status = acpi_get_object_info(handle, &info);
	if (ACPI_SUCCESS(status)) {
		if ((info->address == find->address)
			&& (info->valid & ACPI_VALID_ADR))
			find->handle = handle;
		kfree(info);
	}
	return AE_OK;
}

acpi_handle acpi_get_child(acpi_handle parent, u64 address)
{
	struct acpi_find_child find = { NULL, address };

	if (!parent)
		return NULL;
	acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
			    1, do_acpi_find_child, NULL, &find, NULL);
	return find.handle;
}

EXPORT_SYMBOL(acpi_get_child);

/* Link ACPI devices with physical devices */
static void acpi_glue_data_handler(acpi_handle handle,
				   void *context)
{
	/* we provide an empty handler */
}

/* Note: a success call will increase reference count by one */
struct device *acpi_get_physical_device(acpi_handle handle)
{
	acpi_status status;
	struct device *dev;

	status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
	if (ACPI_SUCCESS(status))
		return get_device(dev);
	return NULL;
}

EXPORT_SYMBOL(acpi_get_physical_device);

static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
	struct acpi_device *acpi_dev;
	acpi_status status;

	if (dev->archdata.acpi_handle) {
		dev_warn(dev, "Drivers changed 'acpi_handle'\n");
		return -EINVAL;
	}
	get_device(dev);
	status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
	if (ACPI_FAILURE(status)) {
		put_device(dev);
		return -EINVAL;
	}
	dev->archdata.acpi_handle = handle;

	status = acpi_bus_get_device(handle, &acpi_dev);
	if (!ACPI_FAILURE(status)) {
		int ret;

		ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
				"firmware_node");
		ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
				"physical_node");
		if (acpi_dev->wakeup.flags.valid)
			device_set_wakeup_capable(dev, true);
	}

	return 0;
}

static int acpi_unbind_one(struct device *dev)
{
	if (!dev->archdata.acpi_handle)
		return 0;
	if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
		struct acpi_device *acpi_dev;

		/* acpi_get_physical_device increase refcnt by one */
		put_device(dev);

		if (!acpi_bus_get_device(dev->archdata.acpi_handle,
					&acpi_dev)) {
			sysfs_remove_link(&dev->kobj, "firmware_node");
			sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
		}

		acpi_detach_data(dev->archdata.acpi_handle,
				 acpi_glue_data_handler);
		dev->archdata.acpi_handle = NULL;
		/* acpi_bind_one increase refcnt by one */
		put_device(dev);
	} else {
		dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
	}
	return 0;
}

static int acpi_platform_notify(struct device *dev)
{
	struct acpi_bus_type *type;
	acpi_handle handle;
	int ret = -EINVAL;

	if (!dev->bus || !dev->parent) {
		/* bridge devices genernally haven't bus or parent */
		ret = acpi_find_bridge_device(dev, &handle);
		goto end;
	}
	type = acpi_get_bus_type(dev->bus);
	if (!type) {
		DBG("No ACPI bus support for %s\n", dev_name(dev));
		ret = -EINVAL;
		goto end;
	}
	if ((ret = type->find_device(dev, &handle)) != 0)
		DBG("Can't get handler for %s\n", dev_name(dev));
      end:
	if (!ret)
		acpi_bind_one(dev, handle);

#if ACPI_GLUE_DEBUG
	if (!ret) {
		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

		acpi_get_name(dev->archdata.acpi_handle,
			      ACPI_FULL_PATHNAME, &buffer);
		DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
		kfree(buffer.pointer);
	} else
		DBG("Device %s -> No ACPI support\n", dev_name(dev));
#endif

	return ret;
}

static int acpi_platform_notify_remove(struct device *dev)
{
	acpi_unbind_one(dev);
	return 0;
}

int __init init_acpi_device_notify(void)
{
	if (platform_notify || platform_notify_remove) {
		printk(KERN_ERR PREFIX "Can't use platform_notify\n");
		return 0;
	}
	platform_notify = acpi_platform_notify;
	platform_notify_remove = acpi_platform_notify_remove;
	return 0;
}
OpenPOWER on IntegriCloud